The invention taught in the present application is closely related to the inventions taught in patent applications titled xe2x80x9cApparatus For A Quick Release Mechanism In A Railcar Hand Brakexe2x80x9d, having Ser. No. 09/664,212, filed on Sep. 18, 2000, now U.S. Pat. No. 6,364,428 and xe2x80x9cElectronic Sensor For A Quick Release Hand Brakexe2x80x9d filed concurrently herewith and having Ser. No. 09/876,337 filed on Jun. 7, 2001, now U.S. Pat. No. 6,364,069.
These applications are assigned to the assignee of the present application. The teachings of these co-pending patent applications are incorporated herein by reference thereto.
The present invention relates, in general, to a mechanical sensor for a quick release mechanism for a railroad car vertical hand brake, and more particularly, to a mechanical sensor that provides a visual signal that the hand brake is in the released position.
Prior to the present invention, a railroad car vertical hand brake includes a brake release mechanism that provides free release of the brakes by disengaging the winding gear to permit free rotation of the main gear wheel. The quick release mechanism maintains a railcar hand brake in the full release position while the train is moving, preventing worn wheels. However, a railroad operator often has to climb onto the railcar to visually determine that the hand brake is released before moving the train. This procedure can be hazardous to the operator, and time-consuming.
In a first aspect, the present invention provides a mechanical sensor for a quick release mechanism in a railcar vertical hand brake having a housing equipped with a flexible clamp on an inside surface of a wall of the housing, and a release shaft having a member disposed perpendicular to and about a circumference thereof, a first element disposed on the member which interposes with the flexible clamp when the release shaft is rotated to both achieve and maintain a full brake release, and a second element disposed on the member to engage a projection on a ratchet wheel when an operating shaft of the hand brake is rotated to disengage the first element from the flexible clamp to allow a brake application. The mechanical sensor comprises a generally hollow housing member having an open end and a substantially closed radially opposed end. The open end is engageable with an outside surface of a wall of the housing at a point radially opposed to the flexible clamp. A first aperture is formed through the substantially closed radially opposed end of the housing member and in substantially axial alignment with a second aperture formed through the housing wall and a third aperture formed through the flexible clamp. A slidable member has a first portion disposed for reciprocal longitudinal movement within the generally hollow housing member, and a second portion of the slidable member is connected to the first portion. The second portion extends outwardly through the first aperture in the radially opposed end of the housing member. At least a portion of the first portion extends through the second aperture formed through the housing wall, and the third aperture formed through the flexible clamp, for engagement with the first element of the member when the release shaft is rotated to achieve and maintain full brake release. The mechanical sensor includes a means for urging the slidable member into a position wherein a predetermined length of the first portion of the slidable member is retracted through the second aperture formed through the housing wall and the third aperture formed through the flexible clamp, thereby indicating that the hand brake is in an applied position.
It is therefore a primary object of the present invention to provide a mechanical sensor for a quick release mechanism in a railcar vertical hand brake, which indicates the present condition of the hand brake.
Another object of the present invention is to provide a mechanical sensor for a quick release mechanism in a railcar vertical hand brake having a visual indicator for the railcar operator that can be seen from the ground, to determine that the hand brake has been fully released without having to climb onto the railcar.
Still a further object of the present invention is to provide a mechanical sensor for a quick release mechanism in a railcar vertical hand brake, which will reduce potential injury to a railcar operator by minimizing the need to climb onto a railcar to determine if the hand brake is released.